For those looking for a cleaner grind Space Case has released their non-magnetic grinder series. The 4 piece non-magnetic aluminum grinder from Space Case is a quality grinder that comes with a pollen sifter for your material. Removing the magnet from the grinder reduces the chance of any break down ending up in your materials.

The small size is 50mm (about 2") which is small enough to comfortably travel with while still being able to handle the job.